Conventional dual-band transmitters use two separate radio frequency (RF) chains, one RF chain for each band. For example, an IEEE 802.11 system has two frequency bands that are used for service: a b/g-band for 2.4 GHz communications, and an a-band for 5 to 6 GHz communications. To support both of these bands, two separate paths (circuits) for two different frequencies are required, one dedicated to the lower band, and one to the upper band. Because conventional dual-band transmitters require two separate RF chains, conventional dual-band transmitters also require a local oscillator (LO) input and associated LO buffer circuits for each RF chain. This, unfortunately, requires sufficient silicon die area to accommodate these RF chains.
Accordingly, what is needed is an improved dual-band transceiver. The dual-band transceiver should be simple and cost-effective. The present invention addresses such a need.